A few functionalities I don't find in Kiri:Moto

Kiri:Moto
1

Hi all,

I’m using Kiri:Moto for generating G-codes for milling, and I couldn’t find some functionalities. I can cheat with my modeling to replace them but it’s not that easy :slight_smile: I tried changing all the available parameters one after another but I was unable to get want I wanted.

1/ Milling a stock which sizes are approximate
I often need to mill a few occurrences of a specific model. To achieve this, I prepare some stocks which sizes are bigger than the part sizes, then mill the top of them until the remaining stock is as high as the part, then I mill the actual part, contouring it. I couldn’t find a way to achieve this with a single G-code generation, so I do it with two models : the first one to adjust and normalize my stocks height, the second one to mill the part from the normalized stocks.
Is this already available, and I didn’t find it ?

2/ Top surface moves, plunge and spindle speeds
It could be interesting to mill at different moves, plunge and spindle speeds depending on the currently processed part, this could certainly speed up the milling process. For example, set all movement, plunge and spindle speeds for some top layers and the perimeters at a fraction of the speeds used for the rest of the milling. It’s quite the same as for 3D printing when you print your first and last layers and perimeters at 50% of the general speed. Thus the speed could be set rather high for the “inner” carving, but much slower for the visible surfaces to get them smooth.

3/ Milling under Z 0
When I mill a part which must be cut through the stock, I prepare the model thinking to this and I “cheat” with the height, modelling a part higher by 0.5 to 1mm than the required actual height. Then I mill on a martyr piece of wood, the bit can plunge in with without damages and the part is totally separated from the stock. I simply need to attach the stock on the martyr with some double-sided tape so it doesn’t move when the part is fully separated from the stock, the part and the rest of the stock stay in-place on the martyr.
Does such a parameter or functionality already exist ? it needs to extend the contouring of the part under Z 0.

Patrice

2

@patrice much of the functionality you seek is coming in the 2.5 release currently in development. As of now, if you want to perform two roughing passes with different settings, you need to generate separate gcode. In 2.5 you will be able to create a “list” of roughing operations with different settings and scopes (areas of the part to work on).

As for milling under Z bottom, there is a “z thru” settings which extends the bottom cuts. And if you want to do a facing / clearing operation on top of the part, set “z top offset”.

3

For #1, would it be sufficient just to always run g-code that assumes the tallest piece of stock? The cutter might cut “air” for the first pass or two, but that’s harmless.

4

Thanks for your answer.
I already tried this option but the air-cut stays “over” the actual part and I get ridges on all sides, I need it to extend to the whole surface of the stock to fully free it.
To explain a bit more my need, here’s an example :

  • say the part is 100 (width) x 150 (length) x 34mm (height)
  • the maximum milling height is 35mm due to the bit length
  • I prepare a stock 120 x 170 x 40mm, it’s easier being loose than very precise as the CNC should do the job
    But then I need the first “air” passes to mill a surface measuring 120mm x 170mm, starting for example at 40 or 41 or 45mm. And once the bit reaches height 34mm, it can start to mill the actual part and contour it. Doing so you get a nice cut part, even if the upper side of the stock isn’t perfectly leveled or if the stock isn’t perfectly aligned on the CNC.
5

Thanks. Now I understand the issue.

6

@Stewart : thanks, I’ll experiment some more.